1. Field of the Invention
The present invention relates to a vehicle manufacturing system for the installation of tire pressure monitoring systems (TPMS) in which the electronic wheel sensors are identified, and verified to the designated vehicle. A digital code is transmitted to identify the wheel sensors and may also specify the location of the wheel sensors on the vehicle.
2. Background Art
Tire pressure monitoring systems (TPMS) have been developed to monitor tire pressure levels and operating temperatures. It has been found that maintaining tire inflation to the proper pressure can improve vehicle performance and gas mileage. Government regulations have recently been adopted that encourage the adoption of tire pressure monitoring systems as original equipment in new vehicles.
Tire pressure monitoring systems have been developed that include a radio frequency link between sensors mounted to the tire or wheel and the vehicle's electrical system. In the vehicle manufacturing process, the tire pressure monitoring sensors must be activated and checked for operability. Tire pressure monitoring systems may be of a low level type wherein the tire pressure monitoring sensors indicate that there is a problem with regard to tire pressure, but do not identify the specific tire that is improperly inflated. Other more sophisticated systems include identification of a specific tire that is improperly inflated to the on-board diagnostic system of the vehicle.
In some manufacturing plants, several parallel assembly lines are provided to manufacture vehicles. In other manufacturing plants, one or more assembly lines may be split into a plurality of parallel line segments for installation of tire pressure monitoring systems, final vehicle assembly operations, and quality assurance testing. While parallel manufacturing lines and operations may improve the efficiency of assembly operations, problems arise when programmable radio frequency devices, such as electronic wheel sensors are installed, programmed and tested.
Radio frequency transmissions between the assembly line and the electronic wheel sensors are used to identify the wheel sensors to the on-board vehicle diagnostic system. Radio frequency transmissions must be limited in range and power. It is difficult to control radio frequency transmissions when production lines and programming stations are located in close proximity to one another, for example, when programming stations and wheel sensors are less than 10 meters apart. When in such close proximity, stray radio frequency transmission from one line programming station may be picked up by another line's programming station. This can result in erroneous programming of electronic wheel sensor identification information and complications in the programming process.
There is a need for a reliable and effective manufacturing system for programming electronic wheel sensors and their associated on-board diagnostic systems. This need is particularly strong in assembly plants having several production lines with multiple programming stations located in close proximity to one another that are used to activate, program and test electronic wheel sensors. With more sophisticated tire pressure monitoring systems, there is a need for a system that identifies the wheel location of an electronic wheel sensor on a vehicle.